The present invention relates to a deviation detecting device, a rotary laser apparatus with the same, and a position determining system with a deviation detecting/correcting device, and more particularly, it relates to a deviation detecting device that detects a deviation angle of a rotary unit of a laser light projector rotating and emitting laser light, a rotary laser apparatus that comprises such a deviation detecting device, and a position determining system.
An optical leveling apparatus has been replaced with a rotary laser apparatus for producing a horizontal reference level in a wide measurement range.
In recent years, the rotary laser apparatus has been increasingly used for the purpose of measurement on elevation and depression angles, especially in order to produce lines and planes on reference elevation and depression angles. The rotary laser apparatus revolves, reciprocally sweeps, and/or stops while emitting laser beam in horizontal directions, so as to produce rotation reference plane, reference segment, reference plane, reference line, and/or reference point. A position determining system has also been used together, which receives laser beam emitted from the rotary laser apparatus to determine a position.
A prior art embodiment of such a rotary laser apparatus capable of producing an inclination reference plane is disclosed in Japanese Patent Laid-Open No. H6-26861. Configuration and features of the prior art rotary laser apparatus will be outlined below.
Referring to FIG. 32, a rotary laser apparatus 951 includes a casing 901 and a laser light projector 903. A concavity 902 shaped in a truncated cone is defined centrally in a top of the casing 901. The laser light projector 903 vertically extends through the center of the concavity 902. The laser light projector 903 is supported at the concavity 902 where a spherical mount 904 provided in the middle of the laser light projector 903 permits it to tilt. The laser light projector 903 has a projector body 920 with projector optics build therein, and a rotary unit 905 having a pentaprism 909 rotatably attached to the projector body 920. The rotary unit 905 is revolved through a drive gear 907 and a sweep gear 908 actuated by a motor 906.
Two sets of inclination mechanisms 910 (only one of which is shown) are positioned around the laser light projector 903. The inclination mechanism 910 actuated by a motor 911 allows the laser light projector 903 to tilt in a direction as required.
The projector body 920 has a laser light projector (not shown) and projector optics (not shown) built therein, and the projector optics includes a collimator lens that collimates incident laser beam from the laser light projector. The laser beam from the projector optics is deflected in horizontal directions by the pentaprism 909 and projected out of a projector window 931.
In operation, the inclination mechanisms 910 adjust an inclination angle at which the laser beam is to be emitted. After being deflected by the pentaprism 909 in a direction orthogonal to a rotation axis of the rotary unit 905, the laser beam is emitted from the laser projector 903 while the rotary unit 905 is being revolved or reciprocally swept in a predetermined angular range, so as to produce an inclined reference plane.
Since the rotary unit 905 of the laser projector 903, which surrounds the pentaprism 909, is rotatably attached to the projector body 920, it is unavoidable that some mechanical maladjustment is caused between the projector body 920 and the rotary unit 905. Resultantly, the rotary unit 905 is in misalignment with the projector body 920, or with the projector optics. Disadvantageously, such s misalignment or deviation angle leads to alteration in a direction in which the laser beam is emitted, or causes errors in a plane produced and a position determined.
Accordingly, it is an object of the present invention to provide a deviation detecting device that detects a deviation angle of a rotary unit of a laser light projector relative to a projector body, and also to provide a rotary laser apparatus incorporated with the deviation detecting device and a position determining system.
It is another object of the present invention to provide a rotary laser apparatus and a position determining system that cooperatively function to use a deviation angle detected by the deviation detecting device and correct a position determined or a plane defined on the detected deviation angle.
To accomplish the above objects, the present invention provides a deviation detecting device that comprises a light emitter attached to a projector body of a laser light projector emitting laser beam, a reflector that is attached to the projector body of the laser light projector for reflecting light emitted from the emitter, and a light receiving element that is attached to the projector body of the laser light projector for receiving light reflected by the reflector, and the deviation detecting device detects a deviation angle of the rotary unit relative to the projector body from a position of light reflected by the reflector and incident upon the light receiving element.
In such a configuration, the light emitted from the light emitting element, after being reflected by the reflector attached to the rotary unit of the laser light projector, is incident upon the light receiving element attached to the projector body of the laser light projector. As the rotary unit of the laser light projector alters in a relative position with the projector body, the light incident upon the reflector is reflected in a varied direction, resulting in the reflected light being incident upon the light receiving element at a varied position. Sequentially sensing the varied position permits a detection of deviation of the rotary unit of the laser light projector.
Preferably, the deviation detecting device according to the present invention further comprises a first capacitor lens used to collimate the light emitted from the light emitter and direct collimated beam at the reflector, and a second capacitor lens used to converge the light reflected by the reflector so as to be incident upon the light receiving element.
With this configuration, the light emitted from the light emitter is redirected in collimated beam at the reflector, and hence, vertical displacement of the reflector would not vary the resultant beam reflected therefrom. This enables the deviation detecting device to detect only an inclination of the reflector.
The light receiving element may be a quadrant, a semiconductor position detector, or a CCD.
Also, the present invention provides a rotary laser apparatus, in combination with the deviation detecting device, which comprises a light projector having a projector body and a rotary unit, and a casing surrounding the projector, so as to emit laser beam originated from the projector while rotating the laser beam, and the projector advantageously has the deviation detecting device.
Moreover, the present invention also provides a position determining system, in combination with a deviation detecting/correcting device, which comprises a rotary laser apparatus and a light sensor receiving laser light emitted from the rotary laser apparatus, so as to determine a position of the laser light incident upon the light sensor and obtain a resultant value of the determined position or use the resultant value to define a plane, and the rotary laser apparatus is a rotary laser apparatus in combination with the deviation detecting device while the light sensor includes an arithmetic operation unit that uses the deviation angle detected by the deviation detecting device to correct the value of the determined position.
With this configuration, the deviation detecting device attached to the rotary laser apparatus detects a deviation angle of the rotary unit of the laser light projector built in the rotary laser apparatus. The detected deviation angle is transmitted to the light sensor. The arithmetic operation unit in the light sensor uses the deviation angle to correct the value of the determined position.